Added gtk_window_group_list_windows override

ext/gtk+/gtk-2.14.overrides

@@ -1,5 +1,31 @@
 %% include gtk-2.12.overrides
 
+%%
+override gtk_window_group_list_windows
+PHP_METHOD
+{
+    GList *list, *item;
+
+    NOT_STATIC_METHOD();
+
+    if (!php_gtk_parse_args(ZEND_NUM_ARGS(), "")){
+        return;
+    }
+
+    list = gtk_window_group_list_windows(GTK_WINDOW_GROUP(PHPG_GOBJECT(this_ptr)));
+
+    array_init(return_value);
+
+    for (item = list; item; item = item->next) {
+        zval *php_item = NULL;
+        GtkWidget *window = item->data;
+        phpg_gobject_new(&php_item, G_OBJECT(window) TSRMLS_CC);
+        add_next_index_zval(return_value, php_item);
+    }
+
+    g_list_free(list);
+}
+
 %%
 deprecate gtk_box_pack_end_defaults
 since GTK+ 2.14, use GtkBox::pack_end() instead
@@ -26,4 +52,4 @@ since GTK+ 2.14, The toolkit-wide \"gtk-enable-tooltips\" property is now used i
 
 %%
 deprecate gtk_toolbar_get_tooltips
-since GTK+ 2.14, The toolkit-wide \"gtk-enable-tooltips\" property is now used instead.
+since GTK+ 2.14, The toolkit-wide \"gtk-enable-tooltips\" property is now used instead.

tests/GtkWindowGroup/list_windows.phpt

@@ -0,0 +1,36 @@
+--TEST--
+GtkWindowGroup->list_windows method
+--SKIPIF--
+<?php
+if(!extension_loaded('php-gtk')) die('skip - PHP-GTK extension not available');
+if(!method_exists('GtkWindowGroup', 'list_windows')) die('skip -GtkWindowGroup->list_windows not available, requires GTK 2.14 or higher');
+?>
+--FILE--
+<?php
+
+$group = new GtkWindowGroup();
+
+$window = new GtkWindow();
+$window2 = new GtkWindow();
+
+//Add a couple of windows to test
+$group->add_window($window);
+$group->add_window($window2);
+
+$list = $group->list_windows();
+
+var_dump(is_array($list));
+
+foreach ($list as $obj){
+    echo $obj.PHP_EOL;
+}
+
+/* Test wrong arg */
+var_dump($group->list_windows(1));
+?>
+--EXPECTF--
+bool(true)
+[GtkWindow object (GtkWindow Gtk+ type)]
+[GtkWindow object (GtkWindow Gtk+ type)]
+PHP Warning:  GtkWindowGroup::list_windows() expects exactly 0 parameters, 1 given in %s on line %d
+NULL